Video (3gp) Resolution on 6131 320 x 240 Problem

[zocks]

After trying a lot of Times to Encode 3gp (mp4 format) Videos in a 320 x 240 Resolution , I start to realize the Phone can Play Videos in 320 x 240 , but Just because stretching the real max resolution of 176 x 144, but not be avaible to show Videos encoded directly on 320 x 240 .. but it seems that S40 3rd Generationhas nothing to do with it, since another S40 Nokia Phones are avaible to show 320 x 240 encoded Files...

So, Am I Right? is it a way to encode 320 x 240 fpr a 6131, or this Phone just cant show it? (May guess is the Processor would not have the Power, since f.e. by rates above 85, The 6131 doesnt play them smoothly anymore... )